循环血量减少时，醛固酮的分泌有何变化？其生理意义如何？

____ has been stated in the annual white book, our national defense budget per year is ___ below the average of devel oped countries and ____ there is a steady increase every year, China won't be a threat to the world. [ ]

A. As; very; even if

B. As it; well; even though

C. As; well; even if

D. As it; very much; even though